Drilling Precautions

Drilling Precautions

1. Holes that would weaken the frame sidemember should not be drilled in the frame.
2. Holes are not to be drilled in the sidemember's top or bottom flange.
3. Holes to mount brackets, out-riggers and supports may be drilled in the vertical frame side rail web with the following restrictions:
- Material between edge of hole and inside of upper or lower flange must not be less than 38 mm (1.496 in) for low carbon steel (36,000 psi yield).
- The minimum edge distance between any 2 holes up to 5/8 inch diameter must be 25 mm (0.984 in). For larger than 5/8 inch diameter holes, the minimum edge distance must be 1.5 times the diameter of the largest hole.
- No holes will be allowed to exceed 20 mm (0.787 in) in diameter.
- Avoid close vertical succession of fasteners.
- All attaching fasteners, including flat washers, must be of high strength steel (Grade 8).